A low critical temperature system-based small molecule and a synthesis method and application thereof

Abstract

The application discloses a kind of low critical temperature system-based small molecules and synthesis method and application in the intelligent dynamic window of modulating light and heat transport made of it.The small molecule is structure of formula 1, R is independently selected from [O-(CH2) a ] b ‑OCH2CH3, a is 1 or 2;b is 2 to 10.The application encapsulates aqueous solution of molecule of formula 1 of specific concentration in two glass interlayers, and makes the intelligent dynamic window of modulating light and heat transport, and the color of intelligent dynamic window can be regulated by the complexation of specific metal ion and terpyridine.Using simple and economical raw materials, the intelligent dynamic window of the application embodies the leap of technology towards the intelligent management system in modern building.

Description

Technical Field

[0001] This invention relates to the field of smart window materials, specifically to a small molecule based on a low critical temperature system, its synthesis method, and its application. Background Technology

[0002] Materials exhibiting responsiveness to external stimuli have always attracted widespread attention. External stimuli can be divided into two main categories: chemical stimuli such as pH, solvents, ionic strength, and redox reactions, and physical stimuli such as light, heat, electricity, and mechanical force. Thermal stimuli are readily available; thermally responsive materials disperse uniformly within a certain temperature range, and phase separation occurs above this temperature (LCST) or below it (UCST), causing the system to become turbid. Poly(N-isopropylacrylamide) (PNIPAM) was the first LCST-type thermosensitive polymer reported by scientist Scarpa in 1967. For a long time, research on LCST-type thermosensitive materials was limited to polymer systems, especially supramolecular systems, such as crown ethers, cyclodextrins, calixarenes, columnar aromatics, cucurbituril, and other macrocyclic structures and ionic liquids. However, LCST-type thermosensitive materials based on small molecules have rarely been reported.

[0003] Compared to polymer systems, small molecules offer the advantage of precise and controllable synthesis. Furthermore, compared to small molecule systems that require additional energy to control LCST behavior, LCST-type thermosensitive materials based on naturally temperature-controlled small molecules have enormous application potential, such as responsive materials for smart windows. Chinese Patent Publication No. CN114466835A discloses a thermoresponsive molecule for controlled heat and light transmission windows and its applications. However, the chemical structure synthesis in this disclosure is relatively complex and not concise; additionally, the smart window is pale yellow in its natural state below LCST, affecting visibility; furthermore, the color of this smart window can only be controlled by adding dyes, and the switching between transparency and turbidity in the aqueous solution of the thermoresponsive molecule in this disclosure is not rapid enough, indicating poor sensitivity. Summary of the Invention

[0004] This invention aims to overcome the shortcomings of existing small-molecule-based LCST-type thermosensitive materials, such as cumbersome synthesis, unsightly solution color affecting visibility in the natural state, and poor thermosensitivity. It provides a simple synthesis method for a small molecule based on a low critical temperature system. The molecule's aqueous solution is colorless and transparent in the natural state. Through complexation of functional groups, it can form novel and diverse superamphilic molecular assemblies, allowing for the control of a series of minimum critical dissolution temperatures and color, while also exhibiting excellent thermosensitivity. The invention also provides a synthesis method and its application in the fabrication of intelligent dynamic windows capable of modulating light and heat transmission.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0006] The first aspect of the present invention relates to the molecule of Formula 1:

[0007]

[0008] Wherein, R is independently selected from [O-(CH2)]. a ] b -OY, where a is 1 or 2; b is 2 to 10; Y is selected from -CH3, -CH2CH3, -CH2CH2CH3, and -CH(CH3)2.

[0009] A method for preparing a molecule with thermally responsive formula 1 includes the following steps:

[0010] Under the protection of an inert gas, intermediate 1 With intermediate 2 The activator is dissolved and stirred evenly, and a condensing agent is added under ice bath conditions to react, followed by separation to obtain the product.

[0011] Furthermore, the condensing agent is dicyclohexylcarbodiimide, the activator is 4-dimethylaminopyridine, the molar ratio of intermediate 2 to intermediate 1 is 1:1 to 1.5, the reaction temperature of intermediate 1, intermediate 2 and activator is 20 to 40 °C, and the reaction time is 0.5 to 2 hours; the molar ratio of intermediate 1 to activator is 1:0.08 to 0.2, the molar ratio of intermediate 1 to condensing agent is 1:1 to 1.1, the reaction temperature after adding condensing agent is 20 to 40 °C, and the reaction time is 24 to 48 hours. The molecule of formula 1 is directly synthesized from intermediate 1 and intermediate 2 in one step, with a yield of 64%. The synthesis method is efficient and simple.

[0012] Furthermore, the preparation method of intermediate 1 includes the following steps:

[0013] (1) HO-[(CH2) a -O] b -Y, catalyst, and acid-binding agent are dissolved in a solvent, and p-toluenesulfonyl chloride is added to react, yielding TsO-[(CH2)] by separation. a -O] b -Y;

[0014] (2) Take the TsO-[(CH2) obtained in step (1) a -O] b -Y was dissolved in a solvent with methyl gallate, an acid-binding agent was added, and the reaction was carried out under an inert atmosphere and heated to obtain compound 1.

[0015]

[0016] (3) Dissolve compound 1 obtained in step (2) in a solvent, add an alkaline hydrolysis reagent to react, and separate intermediate 1.

[0017] Furthermore, in step (1), a is 1 or 2, b is 2 to 10, Y is selected from -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2, the catalyst is 4-dimethylaminopyridine, the acid-binding agent is triethylamine, and HO-[(CH2) a -O] b The molar ratio of -Y: p-toluenesulfonyl chloride: catalyst: acid-binding agent is 1:1~2:2~2.5:0.1~0.2, the reaction temperature is 20~40℃, and the reaction time is 24~48 hours;

[0018] The acid-binding agent in step (2) is potassium carbonate, and methyl gallate: TsO-[(CH2)] a -O] b -Y: The molar ratio of the acid-binding agent is 1:3 to 3.2:4 to 5, the reaction temperature is 45 to 65°C, and the reaction time is 48 to 84 hours;

[0019] The alkaline hydrolysis reagent in step (3) is potassium hydroxide or sodium hydroxide, the molar ratio of compound 1 to alkaline hydrolysis reagent is 1:4 to 6, the reaction temperature is 20 to 40°C, and the reaction time is 10 to 24 hours;

[0020] Furthermore, the preparation method of intermediate 2 includes the following steps:

[0021] (4) Dissolve 2-acetylpyridine, 4-methylbenzaldehyde, and ammonia in a solvent, add an acid-binding agent, and heat to react, then separate compound 2.

[0022] (5) The compound 2 obtained in step (4) was dissolved in a solvent with an organic brominated reagent. After adding an initiator, the mixture was heated under an inert atmosphere to react and the compound 3 was separated.

[0023] (6) The compound 3 obtained in step (5) was reacted with ammonia water dissolved in a solvent, and intermediate 2 was obtained by separation.

[0024] Furthermore, in step (4), the ammonia water contains 25% to 28% ammonia, the acid-binding agent is potassium hydroxide or sodium hydroxide, the molar ratio of 4-methylbenzaldehyde: 2-acetylpyridine: acid-binding agent is 1:2 to 2.5:2 to 2.5, the reaction temperature is 20 to 40°C, the reaction time is 24 to 36 hours, and the pure product is obtained by recrystallization. The purification method is simple.

[0025] The organic brominating reagent in step (5) is selected from N-bromosuccinimide, 1,3-dibromo-5,5-dimethylhydantoin, pyridinium tribromide, carbon tetrabromide, 5,5-dibromomelinic acid, dibromocyanoacetamide, dibromoisocyanuric acid, 1,3,5-tribromo-1,3,5-triazine-2,4,6-trione, N-bromoacetamide, and N-bromo-o-sulfonylbenzoimide. The initiator is benzoyl peroxide or azobisisobutyronitrile. The molar ratio of compound 2: organic brominating reagent: initiator is 1:1~1.5:0.1~0.2. The reaction temperature is 60~80℃ and the reaction time is 2~12 hours. The pure product is obtained by recrystallization. The purification method is simple.

[0026] The ammonia water in step (6) contains 25% to 28% ammonia, the reaction temperature is 20 to 40°C, the reaction time is 4 to 8 hours, and the pure product is obtained after washing. The purification method is simple. The synthesized benzylamine group has higher activity than aromatic amines, which is conducive to the next step of direct amidation reaction with carboxylic acid group to form a molecule with a stable structure of formula 1.

[0027] A second aspect of the invention relates to a solution comprising molecules of formula 1, wherein R is selected from [O-(CH2)]. a ] b -OY, where a is 1 or 2, b is 2 to 10, and Y is selected from -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2. In the molecule of Formula 1, when Y is selected from -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2, the minimum critical dissolution temperature of the molecule of Formula 1 in solution can be significantly controlled due to the change in the ratio of hydrophilic and hydrophobic segments. The temperature is in the range of 25°C to 42°C.

[0028] A third aspect of the invention relates to solutions comprising molecules of formula 1, wherein R is selected from [O-(CH2)]. a ] b -OY, where a is 1 or 2, b is 2 to 10, and Y is selected from -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2. The concentration of the molecule of Formula 1 in the solvent is in the range of 0.05 mM to 1 mM, wherein the solvent is selected from water, acetonitrile, or a water-acetonitrile binary mixture in the range of 10% to 20% of the total volume. The solution exhibits temperature-adjustable transparency and is colorless and transparent below its minimum critical dissolution temperature (LCST) and becomes opaque above its minimum critical dissolution temperature (LCST), wherein the temperature is in the range of 25°C to 42°C.

[0029] A fourth aspect of the invention relates to a molecule of formula 1 exhibiting thermally responsive behavior, wherein the molecule is colorless and transparent in its aqueous solution and exhibits a minimum critical solution temperature (LCST) phase transition close to room temperature, wherein the solution is capable of intelligent dynamic windowing that enables rapid changes in transparency within 1.5 to 10 °C, thereby modulating light and heat transfer through rapid and reversible switching of optical transparency.

[0030] The fifth aspect of this invention relates to a molecular aqueous solution comprising Formula 1, which not only allows for color control by adding water-soluble dyes, but also utilizes the characteristic that terpyridine can form stable complexes with many transition metals and main group metals to incorporate Ru... 3 + Fe 2+ 、Tb 3+ Eu 3+ 、Sm 3+ Gd 3+ The addition of metals to an aqueous solution of the molecule of Formula 1 forms novel and diverse superamphilic molecular assemblies, thereby achieving color tunability covering the RGB color space. The molar ratio of the molecule of Formula 1 to the metal ion is 1:0.001 to 0.5. The concentration of the metal complex of the molecule of Formula 1 in the solvent is in the range of 0.05 mM to 1 mM. The solvent is selected from water, acetonitrile, or a water-acetonitrile binary mixture in the range of 10% to 20% of the total volume. The solution exhibits temperature-tunable transparency and becomes opaque above its minimum critical dissolution temperature (LCST), which is in the range of 30°C to 60°C.

[0031] This invention is based on a small molecule with a low critical temperature system, specifically a small molecule with a lowest critical solution temperature (LCST). An aqueous solution of a molecule of formula 1 at a specific concentration is encapsulated within two glass layers to create a smart dynamic window capable of modulating light and heat transfer. The color of the smart dynamic window can be controlled by complexing a specific metal ion with terpyridine. Using simple and economical raw materials, the smart dynamic window of this invention represents a technological leap towards intelligent management systems in modern architecture.

[0032] This overview aims to briefly introduce the main contents of the present invention. The following specific embodiments will describe the features and advantages of the present invention in detail to help understand the subject matter of the present invention. Attached Figure Description

[0033] Figure 1 It is the structural formula of Formula 1 of this invention.

[0034] Figure 2 yes Figure 1 The proton NMR spectrum.

[0035] Figure 3These are the transmittance-temperature curves and cloud point diagrams of aqueous solutions of molecules of Formula 1 at different concentrations according to the present invention.

[0036] Figure 4 This is a transparent-turbidity switching diagram of the intelligent dynamic window of the present invention containing an aqueous solution of a molecule of Formula 1 at a concentration of 1 mM. Detailed Implementation

[0037] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0038] In one embodiment of this disclosure, an example of a molecule of thermally responsive formula 1 is provided. This disclosure is not limited to the specific methods and experimental conditions described, as such methods and conditions may be applicable.

[0039] Example 1. Synthesis of 3,6,9,12-tetraoxotetradecyl-4-methylbenzenesulfonate

[0040] In a dry 100 mL round-bottom flask, add 3,6,9,12-tetraoxotetradecane-1-ol (5.0 g, 22.5 mmol), 4-dimethylaminopyridine (275 mg, 2.3 mmol), triethylamine (4.6 g, 45.0 mmol), and 30 mL of dichloromethane. Dissolve p-toluenesulfonyl chloride (6.4 g, 33.7 mmol) in 20 mL of dichloromethane and pour the solution into a constant pressure dropping funnel. Slowly add the solution dropwise to the system under ice bath conditions for 1 hour. After restoring to room temperature (25 °C), react for 24 hours. Remove the solvent by rotary evaporation. Add 50 mL of water and 50 mL of dichloromethane and allow to stand for separation. Extract the aqueous phase with dichloromethane (3 × 50 mL). Combine the organic phases, wash with saturated brine (2 × 100 mL), separate, and evaporate to dryness. The crude product was purified by column chromatography to give a yellow oily compound, 3,6,9,12-tetraoxotetradecyl-4-methylbenzenesulfonate (4.7 g, 56%). TLC (petroleum ether:ethyl acetate = 1:1) f =0.5, 1 H NMR (400MHz, CDCl3, 278K) δ (ppm): 7.78 (d, J = 8.3Hz, 2H), 7.33 (d, J = 8.1Hz, 2H ),4.17–4.12(m,2H),3.68–3.49(m,17H),2.43(s,3H),1.19(t,J=7.0Hz,3H). 13 C NMR (101MHz, CDCl3, 298K) δ (ppm): 144.89, 133.08, 129.92, 128.08, 70.82, 70.73, 70.69, 70.64, 70.60, 69.89, 69.35, 68.76, 66.72, 21.73, 15.24.

[0041] Example 2. Synthesis of Compound 1

[0042] Under nitrogen protection, methyl gallate (0.3 g, 1.7 mmol), 3,6,9,12-tetraoxotetradecyl-4-methylbenzenesulfonate (2.0 g, 5.3 mmol), potassium carbonate (1.0 g, 7.6 mmol), and 10 mL of acetone were added to a 50 mL three-necked flask, and the mixture was heated to reflux at 56 °C for 72 h. After removing the solvent by rotary evaporation, the product was dissolved in a suitable amount of dichloromethane, filtered through a suitable amount of diatomaceous earth to remove excess potassium carbonate, and then evaporated to dryness. The crude product was purified by column chromatography to give a brown oily compound 1 (1.2 g, 89%). TLC (dichloromethane:methanol = 15:1) R f =0.72, 1 HNMR (400MHz, CDCl3, 278K) δ (ppm): 7.27 (s, 2H), 4.22–4.15 (m, 6H), 3.85 (dd, J = 8.9, 3.6Hz, 7H), 3.80–3.75 (m, 2H) ),3.69(ddd,J=6.8,5.9,3.3Hz,6H),3.67–3.59(m,27H),3.58–3.54(m,7H),3.53–3.47(m,7H),1.20–1.16(m,9H). 13 C NMR (101MHz, CDCl3, 298K) δ (ppm): 166.68, 152.37, 142.60, 125.04, 109.06, 70.73, 69.89, 69.69, 68.90, 66.71, 53.54, 52.26, 15.24.ESI-MS calcd.for C 38 H 69 O 17 [M+H] + =797.4529,[M+NH3] + =814.4756, [M+Na] + =819.4349,found797.4519,814.4748,819.4328.

[0043] Example 3. Synthesis of Intermediate 1

[0044] In a 50 mL round-bottom flask, compound 1 (1.2 g, 1.5 mmol), potassium hydroxide (0.4 g, 7.5 mmol), 9 mL ethanol, and 1 mL water were added and stirred at 25 °C for 10 h. The solvent was removed by rotary evaporation. 50 mL of 2 M hydrochloric acid and 50 mL of dichloromethane were added, and the mixture was stirred for 15 min. After standing, the aqueous phase was separated, and the organic phases were extracted with dichloromethane (3 × 50 mL). The organic phases were combined, washed with saturated brine (2 × 100 mL), and evaporated to dryness. The crude product was purified by column chromatography to give a pale yellow oily intermediate 1 (1.2 g, 99%). TLC (dichloromethane:methanol = 10:1) R f =0.42,1H NMR (400MHz, CDCl3, 278K) δ (ppm): 7.37 (s, 2H), 4.48–4.01 (m, 6H), 4.01–3.83 (m, 4H), 3.79 (dd ,J=5.6,4.5Hz,2H),3.73–3.57(m,36H),3.52(p,J=7.1Hz,6H),1.20(td,J=7.0,3.0Hz,9H).13C NMR (101MHz, CDCl3, 298K) δ (ppm): 169.09, 152.29, 142.79, 124.86, 109.57, 77.48, 77.16, 76.84, 72.4 6,71.98,70.89,70.70,70.67,70.64,70.62,70.57,69.85,69.77,68.88,66.74,15.20,15.17.ESI-MS calcd.forC37H66O17[M+H]+=783.4373,[M+NH3]+=800.4638,[M+Na]+=805.4198,found783.4369,800.4605,805.4176.

[0045] Example 4. Synthesis of Compound 2

[0046] In a 250 mL round-bottom flask, 2-acetylpyridine (4.8 g, 40 mmol), 4-methylbenzaldehyde (2.4 g, 20 mmol), 60 mL of ammonia (25-28%), potassium hydroxide (6.2 g, 20 mmol), and 100 mL of ethanol were added, and the mixture was reacted at 30 °C for 24 h. The reaction mixture was filtered to give a pale green solid, which was recrystallized from ethanol to give white crystalline compound 2 (2.9 g, 44%). 1H NMR (400MHz, CDCl3, 278K) δ (ppm): 8.74–8.73 (m, 4H), 8.68 (d, J = 8.0Hz, 2H), 7.86 (t,J=7.8,1.8Hz,2H),7.81(d,J=8.2Hz,2H),7.37–7.31(m,4H),2.43(s,3H).13C NMR (101MHz, CDCl3, 298K) δ (ppm): 156.41, 155.92, 150.28, 149.18, 139.22, 137.01, 135.54, 129.77, 127.26, 123.90, 121.51, 118.75, 21.40.

[0047] Example 5. Synthesis of Compound 3

[0048] Under nitrogen protection, compound 2 (2.0 g, 6.2 mmol), N-bromosuccinimide (1.4 g, 8.0 mmol), azobisisobutyronitrile (0.1 g, 0.62 mmol), and 20 mL of anhydrous ethyl acetate were added to a 50 mL three-necked flask, and the mixture was refluxed at 75 °C for 2 h. The solvent was removed by rotary evaporation of the reaction mixture, and recrystallization from acetone / ethanol at a ratio of 1:2 gave compound 3 (1.0 g, 42%) as a pale yellow solid. 1H NMR (400MHz, CDCl3, 278K) δ (ppm): 8.77–8.71 (m, 4H), 8.68 (d, J = 8.0Hz, 2H), 7 .95–7.86(m,4H),7.54(d,J=8.3Hz,2H),7.37(ddd,J=7.5,4.8,1.2Hz,2H),4.5 7(s,2H).13CNMR(101MHz,CDCl3,298K)δ(ppm):1566.12,156.01,149.61,149 .17,138.76,138.64,137.14,129.77,127.89,124.05,121.55,118.96,33.11.

[0049] Example 6. Synthesis of Intermediate 2

[0050] Under nitrogen protection, 20 mL of tetrahydrofuran and 40 mL of ammonia (25-28%) were added to a 250 mL round-bottom flask and stirred until homogeneous. Compound 3 (1.8 g, 4.47 mmol) was dissolved in 40 mL of tetrahydrofuran and poured into a constant-pressure dropping funnel. The solution was slowly added dropwise to the system over 4 hours, and the mixture was stirred at 25 °C for another 4 hours. The solvent was removed by rotary evaporation, and the solution was dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain a pale yellow solid intermediate 2 (1.4 g, 90%). 1H NMR (400MHz, CDCl3, 278K) δ (ppm): 8.73 (d, J = 4.4Hz, 4H), 8.67 (d, J = 8.0Hz, 2H), 7.93– 7.84(m,4H),7.46(d,J=8.1Hz,2H),7.35(ddd,J=7.4,4.8,1.1Hz,2H),3.96(s,2H).13C NMR (101MHz, CDCl3, 298K) δ (ppm): 156.35, 156.00, 150.05, 149.22, 144.26, 137.00, 127.74, 127.58, 123.94, 121.50, 118.81, 46.24.

[0051] Example 7. Synthesis of the molecule of Formula 1

[0052] Under nitrogen protection, intermediate 1 (0.5 g, 0.6 mmol), intermediate 2 (185 mg, 0.5 mmol), 4-dimethylaminopyridine (6 mg, 0.05 mmol), and 10 mL of anhydrous dichloromethane were added to a 50 mL three-necked flask and stirred at 25 °C for 0.5 h. Dicyclohexylcarbodiimide (124 mg, 0.6 mmol) and 5 mL of anhydrous dichloromethane were then slowly added dropwise to the system through a constant pressure dropping funnel over 20 min. The reaction was continued at 25 °C for 24 h. 15 mL of water was added, and the mixture was allowed to stand and separate. The aqueous phase was extracted with dichloromethane (3 × 15 mL). The organic phases were combined, washed with saturated brine (2 × 20 mL), and evaporated to dryness. The crude product was purified by column chromatography to give a yellow oily molecule of formula 1 (336 mg, 61%). TLC (dichloromethane:methanol = 10:1) R f=0.42,1H NMR (400MHz, CDCl3, 278K) δ (ppm): 8.74 (s, 2H), 8.71 (d, J = 7.9Hz, 1H), 7.97–7.86 (m, 2H), 7.48 (d, J = 8.1Hz, 1H), 7.43–7.37 (m, 1H), 7.22 (s, 1H), 4. 69(d,J=5.7Hz,2H),4.25–4.18(m,3H),3.85–3.81(m,2H),3.80–3.76(m, 1H),3.71–3.67(m,3H),3.61(dt,J=5.7,3.2Hz,12H),3.58–3.53(m,3H),3 .49(dt,J=14.0,6.0Hz,3H),1.18(dt,J=10.1,7.0Hz,5H).13CNMR(101MHz,CDCl3,298K)δ(ppm):167.07,156.15,155.90,152.49,149.98,149.10, 141.56,139.96,137.46,137.19,128.59,127.60,124.02,121.60,118.92 ,107.69,72.41,70.59,69.12,66.73,66.71,43.77,15.23,15.20.ESI-MS calcd.for C59H82N4O16[M+H]+=1103.5799,[M+Na]+=1125.5618,[M+Na++H]+ / 2=563.2845,[M+2Na]+ / 2=574.2755, found 1103.5789,1125.5610,563.2855,574.2766.

[0053] In one embodiment of the present invention, the manufacturing method of the intelligent dynamic window is as follows: three 5×75×1mm polytetrafluoroethylene strips are sandwiched between three sides of two 80×80×3mm ordinary glass pieces, and the three sides are sealed with UV-curable adhesive to obtain a double-glazed window with a 1mm interlayer. After injecting an aqueous solution of the molecules of Formula 1 into the interlayer, the fourth side is sealed with 5×75×1mm polytetrafluoroethylene and UV-curable adhesive to obtain an intelligent dynamic window.

[0054] like Figure 3 As shown, the permeability-temperature curve of the aqueous solution of the molecule of Formula 1 indicates that the minimum critical dissolution temperature can be controlled from 30°C to 42°C in the concentration range from 1 mM to 0.05 mM, and the permeability of the 1 mM solution can be completely converted from 100% to 0% within 1.5°C, showing excellent sensitivity.

[0055] like Figure 4 As shown, the intelligent dynamic window prepared by the present invention exhibits a transparent-opaque transition under natural conditions. The intelligent dynamic window is completely transparent and visible below the minimum critical dissolution temperature, and becomes opaque above the minimum critical dissolution temperature, thus possessing temperature responsiveness.

[0056] In another embodiment of the invention, the intelligent dynamic window interlayer comprises an aqueous solution of molecules of Formula 1, wherein R is selected from [O-(CH2)]. a ] b -OCH2CH3, a is 1 or 2, b is 2 to 10, an aqueous solution of a molecule of formula 1, with a concentration in the range of 0.05 mM to 1 mM, wherein the solvent is selected from water, acetonitrile, or a water-acetonitrile binary mixture wherein the amount of acetonitrile is in the range of 10% to 20% of the total volume, the solution exhibits temperature-adjustable transparency, and the solution becomes opaque above its minimum critical dissolution temperature (LCST), said temperature being in the range of 30°C to 42°C.

[0057] In another embodiment of the invention, the aqueous solution of the molecules of Formula 1 contained in the intelligent dynamic window interlayer can not only control the color by adding water-soluble dyes, but also utilize the characteristic of terpyridine to form stable complexes with many transition metals and main group metals to transfer Ru... 3+ Fe 2+ 、Tb 3+ Eu 3+ 、Sm 3+ Gd 3+ The addition of a metal to an aqueous solution of a molecule of Formula 1 forms a complex, thereby achieving color tunability covering the RGB color space, wherein the molar ratio of the molecule of Formula 1 to the metal ion is 1:0.001 to 0.2, the concentration of the metal complex of the molecule of Formula 1 in the solvent is in the range of 0.05 mM to 1 mM, wherein the solvent is selected from water, acetonitrile, or a water-acetonitrile binary mixture wherein the amount of acetonitrile is in the range of 10% to 20% of the total volume, the solution exhibits temperature-tunable transparency, and the solution becomes opaque above its minimum critical dissolution temperature (LCST), said temperature being in the range of 30°C to 50°C.

[0058] In another embodiment of the invention, the intelligent dynamic window is colorless and transparent below the lowest critical melting temperature (LCST) and exhibits a significant change in transmittance when approaching the LCST temperature (30°C to 42°C). The intelligent dynamic window can achieve a rapid change in transparency within 1.5 to 10°C, thereby modulating light and heat transmission through rapid and reversible switching of optical transparency.

[0059] In another embodiment of the invention, the intelligent dynamic window has reversible transparency control and color adjustability at near room temperature (30°C to 42°C) for the effective management and utilization of energy in the building's indoor environment.

Claims

1. A small molecule based on a low critical temperature system, characterized in that, For the structure of Equation 1: Wherein, R is independently selected from [O-(CH2)]. a ] b -OY, where a is 1 or 2; b is an integer from 2 to 10; Y is selected from -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2.

2. The method for synthesizing small molecules based on a low critical temperature system according to claim 1, characterized in that, Includes the following steps: Under gas protection, intermediate 1 With intermediate 2 The activator is dissolved and stirred evenly to carry out the first step reaction. Then, a condensing agent is added to carry out the second step reaction, and the small molecule based on the low critical temperature system with the structure of Formula 1 is separated. The R in intermediate 1 has the same meaning as the R in the structure of Equation 1.

3. The method for synthesizing small molecules based on a low critical temperature system according to claim 2, characterized in that, The activator is 4-dimethylaminopyridine, and the condensing agent is dicyclohexylcarbodiimide.

4. The method for synthesizing small molecules based on a low critical temperature system according to claim 2, characterized in that, The molar ratio of intermediate 2 to intermediate 1 is 1:1 to 1.5; The molar ratio of intermediate 1 to activator is 1:0.08 to 0.2; The molar ratio of intermediate 1 to condensing agent is 1:1 to 1.

1.

5. The method for synthesizing small molecules based on a low critical temperature system according to claim 2, characterized in that, The conditions for the first step reaction are: reaction temperature of 20-40℃ and reaction time of 0.5-2 hours; The conditions for the second step reaction are: reaction temperature of 20-40℃ and reaction time of 24-48 hours.

6. The method for synthesizing small molecules based on a low critical temperature system according to claim 2, characterized in that, The preparation of intermediate 1 includes: (1.1) HO-[(CH2) a -O] b -Y, catalyst, and acid-binding agent are dissolved in a solvent, and p-toluenesulfonyl chloride is added to react, yielding TsO-[(CH2)] by separation. a -O] b -Y; (1.2) Take the TsO-[(CH2) obtained in step (1.1) a -O] b -Y and methyl gallate were dissolved in a solvent, an acid-binding agent was added, and the reaction was carried out under a protective gas atmosphere and heated to obtain compound 1. (1.3) Dissolve compound 1 obtained in step (1.2) in a solvent, add an alkaline hydrolysis reagent to react, and separate intermediate 1.

7. The method for synthesizing small molecules based on a low critical temperature system according to claim 6, characterized in that, In step (1.1), the catalyst is 4-dimethylaminopyridine, and the acid-binding agent is triethylamine. The HO-[(CH2)] a -O] b The molar ratio of -Y: p-toluenesulfonyl chloride: catalyst: acid-binding agent is 1:1~2:2~2.5:0.1~0.2, the reaction temperature is 20~40℃, and the reaction time is 24~48 hours; In step (1.2), the acid-binding agent is potassium carbonate; The methyl gallate described: TsO-[(CH2)] a -O] b -Y: The molar ratio of the acid-binding agent is 1:3 to 3.2:4 to 5, the reaction temperature is 45 to 65°C, and the reaction time is 48 to 84 hours; In step (1.3), the alkaline hydrolysis reagent is potassium hydroxide or sodium hydroxide; The molar ratio of compound 1 to alkaline hydrolysis reagent is 1:4 to 6, the reaction temperature is 20 to 40°C, and the reaction time is 10 to 24 hours.

8. The method for synthesizing small molecules based on a low critical temperature system according to claim 2, characterized in that, The preparation of intermediate 2 includes: (2.1) 2-Acetylpyridine, 4-methylbenzaldehyde, and ammonia were dissolved in a solvent, and an acid-binding agent was added. The mixture was then heated to react, and compound 2 was obtained by separation. (2.2) Compound 2 obtained in step (2.1) was dissolved in a solvent with an organic brominated reagent. After adding an initiator, the mixture was heated under a protective gas atmosphere to react and obtain compound 3. (2.3) The compound 3 obtained in step (2.2) was dissolved in a solvent, and after adding ammonia, the reaction was carried out to obtain intermediate 2.

9. The method for synthesizing small molecules based on a low critical temperature system according to claim 8, characterized in that, In step (2.1), the acid-binding agent is potassium hydroxide or sodium hydroxide; The molar ratio of 4-methylbenzaldehyde: 2-acetylpyridine: acid-binding agent is 1:2-2.5:1-2.5, the reaction temperature is 20-40℃, and the reaction time is 24-36 hours. In step (2.2), the organic brominating agent is selected from one of N-bromosuccinimide, 1,3-dibromo-5,5-dimethylhydantoin, pyridinium tribromide, carbon tetrabromide, 5,5-dibromomelinic acid, dibromocyanoacetamide, dibromoisocyanuric acid, 1,3,5-tribromo-1,3,5-triazine-2,4,6-trione, N-bromoacetamide, and N-bromo-o-sulfonylbenzeneimide; The initiator is benzoyl peroxide or azobisisobutyronitrile; The molar ratio of compound 2: organic brominated reagent: initiator is 1:1 to 1.5:0.1 to 0.2, the reaction temperature is 60 to 80°C, and the reaction time is 2 to 12 hours; In step (2.3), the reaction temperature is 20-40℃ and the reaction time is 4-8 hours.

10. The application of the small molecules based on the low critical temperature system according to claim 1 in the preparation of intelligent dynamic windows capable of modulating light and heat transmission.

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